The purpose of this study is to test the hypothesis that muscle neovascularization provides sufficient perfusion for viability. Four rat gastrocnemius muscles (2 cm lon, 1 cm wide, and 0l4 cm thick) will include control, delay, transposition and acute ligation. The control muscle will have no surgery. On day 1, other muscles will be isolated on a vascular pedicle and rotated. On day 7, the delay muscle will have the pedicle ligated. On day 14, the acute ligation muscle will have the pedicle ligated. Saline with gadolinium-labeled albumin will be infused into the hindlimb, followed by glutaraldehyde. The muscle will then be fixed for two more hours and imaged. Five random fields from the distal muscle and five from the proximal muscle will have vascular length density measured. We will use the preliminary data to submit grant proposals to NIH and other agencies for further funding. Factors which modulate vascular remodeling will be the topics of future studies.